CVE-2026-80793 Affecting linux-6.12 package, versions <6.12.107-1~deb12u1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-ECHOLATEST-LINUX612-19964475
- published20 Sept 2026
- disclosed4 Sept 2026
Introduced: 4 Sep 2026
NewCVE-2026-80793 (opens in a new tab)How to fix?
Upgrade Echo:latest linux-6.12 to version 6.12.107-1~deb12u1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
ipv4: reject undersized MTUs in ip_do_fragment()
ip_do_fragment() subtracts the IPv4 header length from the effective MTU and passes the resulting payload MTU to ip_frag_next().
If the effective MTU is smaller than hlen + 8, ip_frag_next() rounds the fragment payload length down to zero. The fragmentation state then never makes forward progress: state->left, state->ptr and state->offset stay unchanged while ip_do_fragment() keeps allocating and transmitting header-only fragments until the softlockup detector fires.
This is reproducible with a route installed using "mtu lock 20", but it is also reproducible without route MTU lock, for example by forwarding a packet to a device whose MTU is 20.
Fix it in ip_do_fragment() by rejecting mtu < hlen + 8 with -EMSGSIZE, matching the existing IPv6 fragmentation check.
References
- https://advisory.echohq.com/cve/CVE-2026-80793
- https://git.kernel.org/stable/c/3556beb8ca86677af2aca5bfbed6f8e790fccc83
- https://git.kernel.org/stable/c/36e0741833bd823866f8cb9f112f37cea1a70b60
- https://git.kernel.org/stable/c/515b6816ba0c12d8415c88e5f41e6ec029e35cfa
- https://git.kernel.org/stable/c/74ce7389f8f562d39015f59a00ef7ad6acd37803
- https://git.kernel.org/stable/c/a716a64a4ba68cd46f2745fba2b1099fe8e0aa59
- https://git.kernel.org/stable/c/b0ea911453ce7210e8200a07a94d2458bd1e6430
- https://git.kernel.org/stable/c/c0726f0caf8c6b3208552949e17d23634a2f3129
- https://git.kernel.org/stable/c/c8a74adccaf028223054633b532593101dfcc581
- https://git.kernel.org/stable/c/d9d1a676b033acabf8e5645f730486d1f8204a3f